Latch for movable lids.



N0. 891,887. PATENTED JUNE 30, 1908. J. E. WALLACE.

LATGH FOR MOVABLE LIDS.

APPLICATION FILED MAY 23- 1907.

l/l/ITNESSES //v VEN 70/? JOHN E. WALLACE, OF WOBURN, MASSACHUSETTS.

LATCH FOR MOVABLE LIDS.

Specification of Letters Patent.

Patented June 30, 1908.

Application filed May 23, 1907. Serial No. 375,219.

To all whom it may concern:

Be it known that I, JOHN E. WALLAcE, citizen of the United States,residing at Woburn, in the county of Middlesex and State ofMassachusetts, have invented certain new and useful Improvements inLatches for Movable Lids; and I do hereby declare the following to be afull, clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame.

The resent invention relates to an im proved atch or clamp for holding amovable id or cover in position. The latch is intended primarily for usein connection with the movable cover or lid of the casing of a railwayelectric motor, but is also capable of use in other relations.

A railway electric motor is provided with a casing which completelyincloses the motor except for an opening above the commutator throughwhich access may be had to the commutator and brushes. This open ing isclosed by means of a cover or lid hinged at one end, and secured at theother end by a clamping device. This clamping device as heretoforeconstructed has proved unsatisfactory and unreliable, the vibrations ofthe motor casing often causing the latch to be displaced so as torelease the cover and per mit the cover to be thrown upwardly so as toexpose the commutator and brushes. The release of the cover by the latchnot only leaves the commutator and brushes unprotected, but permits thecover to move in such a manner that it is often broken or torn from itshinges. The failure of the latch to properly hold the cover isparticularly n0- ticeable when the latch becomes worn by use.

The object of the present invention is to provide a latch or clamp whichwill securely hold the cover of the motor casing in position regardlessof the amount of the vibration of the motor casing, and regardless ofthe amount of wear produced in use either of the latch or of the portionof the cover with which it engages.

With this object in View, the invention consists in the devices andcombinations of devices hereinafter described and claimed, theadvantages of which will be obvious to those skilled in the art from thefollowing description.

The present invention will be clearly understood from an ins ection ofthe accompanying drawing, in which Figure 1 is a perspective view of aportion of an electric railway motor with the referred form of thepresent invention app ied thereto; Fig. 2 is a detail View in sideeleva' tion of the cover or lid of the motor and the improved latch forholding the cover in position, a portion of the casing of the motorbeing shown in section; and Fig. 3 is a plan view of the cover and latchillustrated in Fig. 2.

1 indicates the casing of the motor, of wellknown construction, and 2the cover plate which closes the opening through which access is had tothe commutator and brushes. The cover is provided at one end with theusual lugs 3 by which it is hinged to a projection on the motor casingby a pin 4. At

its other end the cover is provided with a slot 5 through which the stemof the latch passes, and with projections 6 upon its upper surface whichcooperate with the horizontal arm of the latch to hold the cover inposition, as will be hereinafter explained.

The improved latch illustrated in the drawings consists of a cylindricalbolt or stem 7 provided at its upper end with a horizontally projectingarm 8. The stem 7 is mounted to rotate and slide longitudinally in ahorizontal portion of the casing as illustrated in Fig. 2, which ortionof the casing supports the free end 0' the cover 2 when the cover is inposition over the opening in the casing. The stem 7 is arranged to passthrough the slot 5 in the free end of the cover, and the arm 8 isarranged to engage the upper surface of the cover between theprojections 6, which rojections, when the cover and latch are in t 1eposition illustrated in the drawing, hold the latch against rotation. Atits lower end the stem 7 is provided witha nut 9 which is locked inposition by a pin 10 passing through the stem below the nut, and betweenthe nut and the casing a spring 11 is coiled around the stem. The spring11 acts to force the stem 7 downwardly, so that the arm 8 is pressedfirmly against the upper surface of the cover and the cover is heldsecurely in place, regardless of the vibrations of the motor casing. Thespring also acts automatically to compensate for any wear either of thelatch or of the cover. The cover can be readily released by raising thelatch and rotating it through a half revolu- I tion, a ring 12 mountedin an upward rojection from the arm 8 being provided or this urpose.

It will be understood that the latch illustrated in the drawing andabove specifically described embodies the present invention in itspreferred form, but that the invention may be otherwise embodied asdefined in the claims. It will also be understood that While theinvention has been illustrated and described as applied to the coverplate of the casing of a railway motor, it may also be used in otherrelations.

The invention having been thus described, what is claimed is j 1. Thecombination with a cover plate provided with projections extending fromits upper surface, of a latch consisting of a longitudinally movable androtatable stem, and an arm projecting therefrom and arranged to engagethe u per surface of the cover plate'between saic projections, and aspring acting on the stem to force the arm into en agement with thecover plate, substantially as described.

2. The combination with the casing of an electric railway motor, of acover plate hinged at one end thereto and provided at its other end witha slot and with projections from its up er surface, a latch consistingof a longitudina ly movable and rotatable stem arranged to pass throughthe slot in the cover,

and an arm projecting from the stem ar ranged to engage the uppersurface of the cover between said projections, and a spring acting onthe stem to force the arm into engagement with the cover, substantiallyas described.

In testimony whereof I affix my signature, in presence of two witnesses.

JOHN E. WALLACE. Witnesses:

A. Orrs SMITH, WM. B. DARLING.

